The present invention relates to suturing implements for use in applying sutures or threads. The invention is particularly useful in surgical operations for suturing a member, especially a prosthetic valve, to tissue at the suture site, and the invention is therefore described below with respect to this application.
The surgical replacement of defective heart valves, both the aortic valve and the mitral valve, has become a widely-practiced technique. In such a surgical operation, the defective natural valve is surgically removed, and a prosthetic valve is applied by a number of sutures, varying from 12-20 depending upon the size of the annulus remaining after removing the defective natural valve. In this surgical operation, the prosthetic valve to replace the natural one is usually held in a holder while each of the sutures is individually applied, first to the annulus and then to the valve on the holder; and after all the sutures have been applied to both, the valve is moved into the annulus and is fixed in place by knotting the sutures and trimming their ends. The existing procedures using valve holders and other implements presently available take a considerable length of time because of the large number of sutures which must be applied first to the annulus, and then to the valve, before the valve is moved into position within the annulus. Moreover, such a procedure requires a large number of attendants, particularly because of the many different tissues and different tissue points which must be maintained retracted during the surgical operation. Another very serious difficulty involved in the existing procedure is the danger of entanglement of the sutures because of their large number, and also because of their substantial length which is needed to enable the sutures to be applied to the body annulus and to the valve while the valve is held externally of the body, before the valve can be moved into the body annulus. All these drawbacks in the existing procedures using the presently available implements increase the time required for the surgical operation, the danger to the patient, the fatigue of the surgeon, and the number of attendants required for assistance.
Two surgical techniques are mainly used at the present time in the attachment of a prosthetic valve. One technique uses an "over-and-over" stitch when attaching the valve to the body annulus. A suturing implment particularly useful for this technique is described in our co-pending U.S. patent specification No. 69,635 filed Sept. 2, 1983.
Another popular technique uses a "mattress" stitch including a plurality of pledgets, namely small plastic pressure pads such as of "Teflon" (Reg. T.M.), which distribute over a larger surface the pressure applied by each suture to the body annulus. In this technique, each suture carries a needle at both ends, and each pledget is pierced by both needles of its respective suture. The pledget is applied to the outer side of the body annulus, and the suture is knotted at the inner side of the body annulus.
This "mattress" stitch technique, as presently practiced, is subject to all the above-described drawbacks applicable to the "over-and-over" stitch technique, with the additional drawback that the need to pierce the pledgets by the suture needles further increases the time required for the surgical operation, the danger to the patient, the fatigue of the surgeon, and the number of attendants required for assistance. A still further drawback in this technique, is that by knotting the sutures on the artificial valve itself, there is a possibility that the knot may interfere with the prosthetic valve such as to cause it to mal-function, thereby increasing the danger to the patient.